Recently I've bought some clear dissolveable interfacing. You lay out one sheet of interfacing, place your small bits of fabric, trim, threads, and tiny snippets until the interfacing is covered. Then you add a layer of the interfacing on top. Think of it as a sandwich. Pin around the edges and use your sewing machine to sew randomly all over the interfacing until it looks like the whole mess will hold together.
Then hold it all under running water and watch the stuff dissolve away. Let it dry completely. Sew any areas that might not be secured. Then you can use your piece just like fabric. I'm going to make cuffs and a choker out of mine. Once I have more practice I'll write a hub about it.
Another thing you can do is make fabric covered buttons. Most sewing stores carry the metal bits in their notions section. You can make buttons to match your outfits or add them to hats and brooches.